If you live in a place with a cold winter, you can grow it next to a big window, but you will probably have to shine a grow light on it since you won't have enough hours of daylight for the grass to grow well. Buying a growlight is a cheap solution to this problem.
If you live in a hot place, it gets a little trickier. If you have air-conditioning in your house, you can grow it inside next to the window and it will do great. If not, you can try setting up a fan to blow on it during the day to keep it cooler.
If worse comes to worse, you might have to take a couple of months off during the heat of the summer. I've had to do this a few times, since it gets brutally hot where I live in the summer and I can't leave the AC on all the time. If you can't grow it don't worry though. You can always buy the grass from someone else, or take some of the many super green supplements available.